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<body><hr> [
   <a href="../toc.html">Table Of Contents</a>
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<div class="doctools">
<h1 class="doctools_title">critcl::iassoc(n) 1.1 doc &quot;C Runtime In Tcl (CriTcl)&quot;</h1>
<div id="name" class="doctools_section"><h2><a name="name">Name</a></h2>
<p>critcl::iassoc - CriTcl Utilities: Tcl Interp Associations</p>
</div>
<div id="toc" class="doctools_section"><h2><a name="toc">Table Of Contents</a></h2>
<ul class="doctools_toc">
<li class="doctools_section"><a href="#toc">Table Of Contents</a></li>
<li class="doctools_section"><a href="#synopsis">Synopsis</a></li>
<li class="doctools_section"><a href="#section1">Description</a></li>
<li class="doctools_section"><a href="#section2">API</a></li>
<li class="doctools_section"><a href="#section3">Example</a></li>
<li class="doctools_section"><a href="#section4">Authors</a></li>
<li class="doctools_section"><a href="#section5">Bugs, Ideas, Feedback</a></li>
<li class="doctools_section"><a href="#keywords">Keywords</a></li>
<li class="doctools_section"><a href="#category">Category</a></li>
<li class="doctools_section"><a href="#copyright">Copyright</a></li>
</ul>
</div>
<div id="synopsis" class="doctools_section"><h2><a name="synopsis">Synopsis</a></h2>
<div class="doctools_synopsis">
<ul class="doctools_requirements">
<li>package require <b class="pkgname">Tcl 8.4</b></li>
<li>package require <b class="pkgname">critcl <span class="opt">?3.1?</span></b></li>
<li>package require <b class="pkgname">critcl::iassoc <span class="opt">?1.1?</span></b></li>
</ul>
<ul class="doctools_syntax">
<li><a href="#1"><b class="cmd">::critcl::iassoc::def</b> <i class="arg">name</i> <i class="arg">arguments</i> <i class="arg">struct</i> <i class="arg">constructor</i> <i class="arg">destructor</i></a></li>
</ul>
</div>
</div>
<div id="section1" class="doctools_section"><h2><a name="section1">Description</a></h2>
<p><i class="term">C Runtime In Tcl</i>, or <i class="term"><a href="critcl_pkg.html">CriTcl</a></i> , is a system for compiling C code
embedded in Tcl on the fly and either loading the resulting objects into Tcl for
immediate use or packaging them for distribution.  Use <i class="term"><a href="critcl_pkg.html">CriTcl</a></i> to improve
performance by rewriting in C those routines that are performance bottlenecks.</p>
<p>This document is the reference manpage for the <b class="package">critcl::iassoc</b>
package. This package provides convenience commands for advanced
functionality built on top of the critcl core.</p>
<p>With it a user wishing to associate some data with a Tcl
interpreter via Tcl's <b class="function">Tcl_(Get|Set)AssocData()</b> APIs can now
concentrate on the data itself, while all the necessary boilerplate
around it is managed by this package.</p>
<p>Its intended audience are mainly developers wishing to write
Tcl packages with embedded C code.</p>
<p>This package resides in the Core Package Layer of CriTcl.</p>
<p><img alt="arch_core" src="../image/arch_core.png"></p>
</div>
<div id="section2" class="doctools_section"><h2><a name="section2">API</a></h2>
<dl class="doctools_definitions">
<dt><a name="1"><b class="cmd">::critcl::iassoc::def</b> <i class="arg">name</i> <i class="arg">arguments</i> <i class="arg">struct</i> <i class="arg">constructor</i> <i class="arg">destructor</i></a></dt>
<dd><p>This command defines a C function with the given <i class="arg">name</i> which
provides access to a structure associated with a Tcl interpreter.</p>
<p>The C code code fragment <i class="arg">struct</i> defines the elements of
said structure, whereas the fragments <i class="arg">constructor</i> and
<i class="arg">destructor</i> are C code blocks executed to initialize and release
any dynamically allocated parts of this structure, when needed. Note
that the structure itself is managed by the system.</p>
<p>The new function takes a <b class="const">Tcl_Interp*</b> pointer refering
to the interpreter whose structure we wish to obtain as the first
argument, plus the specified <i class="arg">arguments</i> and returns a pointer to
the associated structure, of type &quot;<i class="arg">name</i>_data&quot; (see below).</p>
<p>The <i class="arg">arguments</i> are a dictionary-like list of C types and
identifiers specifying additional arguments for the accessor function,
and, indirectly, the <i class="arg">constructor</i> C code block. This is useful
for the supplication of initialization values, or the return of more
complex error information in case of a construction failure.</p>
<p>The C types associated with the structure are derived from
<i class="arg">name</i>, with &quot;<i class="arg">name</i>_data__&quot; the type of the structure itself,
and &quot;<i class="arg">name</i>_data&quot; representing a pointer to the structure.
The C code blocks can rely on the following C environments:</p>
<dl class="doctools_definitions">
<dt><i class="arg">constructor</i></dt>
<dd><dl class="doctools_definitions">
<dt><b class="variable">data</b></dt>
<dd><p>Pointer to the structure (type: <i class="arg">name</i>_data) to
initialize.</p></dd>
<dt><b class="variable">interp</b></dt>
<dd><p>Pointer to the Tcl interpreter (type: Tcl_Interp*)
the new structure will be associated with.</p></dd>
<dt>error</dt>
<dd><p>A C code label the constructor can jump to should it have
to signal a construction failure. It is the responsibility of the
constructor to release any fields already initialized before jumping
to this label.</p></dd>
<dt>...</dt>
<dd><p>The names of the constructor arguments specified with
<i class="arg">arguments</i>.</p></dd>
</dl></dd>
<dt><i class="arg">destructor</i></dt>
<dd><dl class="doctools_definitions">
<dt><b class="variable">data</b></dt>
<dd><p>Pointer to the structure being released.</p></dd>
<dt><b class="variable">interp</b></dt>
<dd><p>Pointer to the Tcl interpreter the structure
belonged to.</p></dd>
</dl></dd>
</dl></dd>
</dl>
</div>
<div id="section3" class="doctools_section"><h2><a name="section3">Example</a></h2>
<p>The example shown below is the specification of a simple interpreter-associated
counter. The full example, with meta data and other incidentals, can be found
in the directory &quot;<b class="file">examples/queue</b>&quot; of the critcl source
distribution/repository.</p>
<pre class="doctools_example">
package require Tcl 8.4
package require critcl 3.1
critcl::buildrequirement {
    package require critcl::iassoc
}
critcl::iassoc::def icounter {} {
    int counter; /* The counter variable */
} {
    data-&gt;counter = 0;
} {
    /* Nothing to release */
}
critcl::ccode {
    ... function (...)
    {
         /* Access to the data ... */
         icounter_data D = icounter (interp /* ... any declared arguments, here, none */);
	 ... D-&gt;counter ...
    }
}
# or, of course, 'cproc's, 'ccommand's etc.
package provide icounter 1
</pre>
</div>
<div id="section4" class="doctools_section"><h2><a name="section4">Authors</a></h2>
<p>Andreas Kupries</p>
</div>
<div id="section5" class="doctools_section"><h2><a name="section5">Bugs, Ideas, Feedback</a></h2>
<p>This document, and the package it describes, will undoubtedly contain
bugs and other problems.
Please report such at <a href="https://github.com/andreas-kupries/critcl">https://github.com/andreas-kupries/critcl</a>.
Please also report any ideas for enhancements you may have for either
package and/or documentation.</p>
</div>
<div id="keywords" class="doctools_section"><h2><a name="keywords">Keywords</a></h2>
<p><a href="../index.html#key8">C code</a>, <a href="../index.html#key3">Embedded C Code</a>, <a href="../index.html#key15">Tcl Interp Association</a>, <a href="../index.html#key6">code generator</a>, <a href="../index.html#key0">compile &amp; run</a>, <a href="../index.html#key10">compiler</a>, <a href="../index.html#key1">dynamic code generation</a>, <a href="../index.html#key2">dynamic compilation</a>, <a href="../index.html#key9">generate package</a>, <a href="../index.html#key4">linker</a>, <a href="../index.html#key5">on demand compilation</a>, <a href="../index.html#key7">on-the-fly compilation</a>, <a href="../index.html#key13">singleton</a></p>
</div>
<div id="category" class="doctools_section"><h2><a name="category">Category</a></h2>
<p>Glueing/Embedded C code</p>
</div>
<div id="copyright" class="doctools_section"><h2><a name="copyright">Copyright</a></h2>
<p>Copyright &copy; 2011-2018 Andreas Kupries</p>
</div>
</div></body></html>
